WO1994020293A1

WO1994020293A1 - Ballistic resistant article

Info

Publication number: WO1994020293A1
Application number: PCT/US1994/002686
Authority: WO
Inventors: Wayne Lundblad; Carl Dixon; Harold Colin Ohler
Original assignee: Southern Research Institute
Priority date: 1993-03-12
Filing date: 1994-03-11
Publication date: 1994-09-15
Also published as: DE69425962D1; EP0689501B1; ES2149870T3; ATE196445T1; DE69425962T2; EP0689501A1; US5456974A; EP0689501A4

Abstract

An article of manufacture that contains a plurality of yarns woven into an interlocking 3-dimensional structure whether or not uniform and symmetrical such that said interlocking impedes the penetration of projectiles such as bullets, fragments, flechettes and the like. The articles of the present invention are useful for providing a high degree of ballistic resistance and are therefore useful in armor applications.

Description

BALLISTIC RESISTANT ARTICLE

Cross-Reference to Related Application

This is a continuation-in-part of our copending U.S Patent Application Serial No. 08/013,389, filed March 12 1993, and entitled "Ballistic Resistant Article." DESCRIPTION

Technical Field

The present invention is concerned with an article tha exhibits a relatively high degree of ballistic resistance The articles of the present invention are especially suitabl for providing relatively lightweight ballistic resistan materials of decreased thickness. In particular, the presen invention is concerned with certain woven materials tha exhibit a 3-dimensional weave configuration. The articles o the present invention can be used in providing personal bod armor, as well as armor for various structures, includin vehicles, such as automobiles, planes, helicopters, satellite and especially military vehicles.

Background Art

In order to protect military and law enforcemen personnel from the hazards of projectiles, protective article of clothing, such as vests, shirts and caps are provided. Th typical ballistic resistant woven materials presently employe involve a 2-dimensional weave as shown in Figure 1. In thi type of weave, yarns are woven at right angles to one anothe in directions referred to as warp and weft or fill. The wove material is typically a high modulus material such as fiber of aramid, glass, quartz, polyolefins, such as polypropylen and polyethylene, and various polyesters. In addition certain liquid crystal polymers such as polybenzothiozole an polybenzoxizole have been suggested for such purposes. Spide silk has also been considered by some sources.

The current 2-dimensional weaves are approximately 0.05 inches to about 0.08 inches thick and ballistic resistance is achieved by stacking together as many as thirty layers. The multi-layer panels are usually about 12 inches wide by 12 inches long and can range up to any thickness, depending upon the level of protection desired. For instance, a typical thickness for a class 2A protection (9mm hand gun) is abou 0.5 inches. The ballistic panels are then placed in strategic pockets in vests or jackets or similar articles of clothing to form body armor.

A disadvantage of the presently employed 2-dimensional weave configuration is that an impinging projectile tends to separate the warp and fill yarns as illustrated in Figure 2. Figure 2 illustrates the usual situation where the projectile separates the warp and fill yarns before being stopped at some intermediate layer. The separation caused by an impingin projectile makes it necessary to stack together several layers of the woven material in order to provide any degree o ballistic resistance. Of course, the more layers required, the heavier and less comfortable will be the particular piece of armor. Accordingly, continuing efforts are being made t provide fabrics exhibiting relatively light weight, while a the same time, exhibiting the desired degree of protection. Usually however, comfort is sacrificed for adequat performance. Balancing performance and comfort without prohibitively expensive product is a major problem tha challenges those involved in the design of soft body armor.

Summary of Invention

The present invention provides an article possessin improved ballistic resistance, while at the same time, bein thinner than presently available articles exhibiting simila ballistic resistance. This in turn, makes it possible t provide relatively low weight ballistic resistant material that nonetheless exhibit satisfactory resistance.

In particular, the advantages achieved by the presen invention are obtained by employing any suitable 3-dimensiona weave configuration. The configuration of the presen invention is such that the yarns impede the penetration of a impinging projectile to a far greater extent than tha experienced in conventional 2-dimensional weave configuration of the prior art.

More particularly, the present invention is concerne with an article of manufacture that contains a plurality o yarns in the warp direction (Figure 7) . The number of war yarns of which determine the width and thickness of the fina article (Figure 3) . The thickness of the article is comprise of at least two planes of high modulus warp yarns. More tha two planes of warp yarns constitutes construction of sai article of various thicknesses. In the fill direction a yar is woven such to bind together any plurality of warp yarns the number of which are bound together to determine th desired thickness and construction of the article. I addition, a second fill yarn, located behind the first fil yarn, is shifted over some specified increment in the widt direction to bind together another plurality of warp yarns A third fill yarn, located behind the second fill yarn, i further incremently shifted over in the width direction an ties together another plurality of warp yarns. This shiftin arrangement of yarns is continued throughout substantially th entire width of the warp direction thereby providing a interlocked article. Summary of Drawings

Figure 1 illustrates a conventional prior art dimensional weave. Figure 2 illustrates the effect of an impingi projectile on a typical prior art 2-dimensional weave.

Figure 3 is a schematic diagram of a eight plane wa yarn article.

Figures 4 is a schematic diagram of an eight plane wa yarn article with a fill yarn.

Figure 5 is a schematic diagram of an eight plane wa yarn article with two fill yarns.

Figure 6 is a schematic diagram of an eight plane wa yarn article with three fill yarns. Figure 7 is a 3-dimensional schematic diagram of an eig plane warp yarn complete article.

Figures 8 and 9 illustrate the results of testi performed on an article of the present invention.

Best and Various Modes for Carrying Out the Invention

In order to facilitate an understanding of the presen invention, reference is made to Figures 3 through 7, whic schematically illustrate a particular weave required by th present invention. In particular, Figure 3 shows a pluralit of high modulus warp yarns (1) , arranged as to comprise eigh planes (2) . The yarns (1) , to facilitate an understanding o the present invention, are illustrated as being spaced apar but when woven, will be touching each other. Although Figur 3 illustrates an article comprising eight planes of war yarns, the article can contain as few as two planes of war yarns. The maximum number of warp planes is merely dictate by practical considerations, especially by the desire ballistic resistance for the particular article. The articl contains a minimum of 2 planes of warp yarns, it can contai as many as desired for a required thickness but a preferabl number is about 4-8 planes. In addition, as illustrated in Figure 4, a fill yarn i used to tie together a plurality of warp yarns, referred to a a bundle (3) . Each bundle (3) typically contains at least warp yarns. The maximum number of warp yarns per bundle i merely dictated by practical considerations. Figure illustrates a bundle of 36 warp yarns. The high modulus fil yarns (4) can be any of the materials discussed previousl that are employed for the high modulus warp yarns (1) According to preferred embodiments, the fill yarns (4) will the same material as employed for the warp yarns (1) , but not have to be necessarily so.

Figure 5 illustrates a second fill yarn (4¹) wov directly behind the first fill yarn (4) but shifted over one warp yarn in plane 1 in the width direction. The seco fill yarn (4*) also ties together a bundle of 36 warp yarn The angle (A) of fill yarns is dependent on the bundle si and is typically about 30 to about 120 degrees and, accordi to preferred aspects of the present invention is about 45 about 75 degrees, and most preferably about 60 degrees. course, if desired, angle (A) need not be the same througho the article, but can vary. Figure 6 illustrates a third fill yard (4") wov directly behind the second fill yarn (4') but again shift over by one warp yarn in plane 1 with respect to yarn (4*) a two warp yarns in plane 1 with respect to yarn (4) . The thi fill yarn (4") also ties together 36 warp yarns. Th shifting arrangement of yarns continues througho substantially the entire defined width of the article illustrated in Figure 7.

In addition, as shown in Figures 3-7, according preferred aspects of the invention, the warp yarns in plane are offset from the yarns in both plane l and plane 3 by o yarn to the right in the width direction. The yarns in plan 1 and 3 are aligned with each other, as are the warp yarns planes 5 and 7; whereas the warp yarns in planes 4, 6 and are aligned with those in plane 2, but offset from the wa yarns in the odd numbered planes. This offset arrangeme continues throughout substantially the entire defined heig of the article, as illustrated in Figures 3-7. However, desired, but less preferred, the warp yarns in one plane c be offset by more than one yarn from the warp yarns in adjacent plane. Moreover, it is not necessary that each wa yarn plane be offset from each of its adjacent warp ya planes. It has been found, however, that the preferred offs arrangement, as illustrated in Figures 3-7, provide t highest yarn packing configuration, which in turn, provid for the most effective results for stopping an impingi projectile, fragment, flechette or the like. Figures 5-7 al illustrate the most preferred angle A of about 60 degrees.

This shifting arrangement along with the angl relationship of the yarns in the fill direction provide f the interlocking of the bundles which is critical to achievi the desired results obtained by the present invention. Additionally, all yarns are typically in contact wit corresponding adjacent yarns.

The yarns employed are usually high elastic modulus yarn typically exhibiting a modulus of elasticity of at least abou 10* MPa (megapascals) and more typically at least about 10 MPa.

Examples of some typical high modulus yarns that can b employed pursuant to the present invention are ara id, glas fibers such as E-glass fibers and quartz, polyolefins such a polyethylene and polypropylene, polyesters, nylon, liqui crystal polymers such as polybenzothiozole an polybenzoxizole, and silk. Of course, fiber blends can b used, if desired. In addition, yarns in the warp direction and/or yarns i the fill direction can all be of the same material or can b of two or more different materials in any arrangement. Fo example, certain yarns in the warp direction could be of on type of material, while the other yarn in the warp directio could be of another material. It is preferred that th article obtained be flexible.

The article typically at the end where the weaving i begun contains the various yarns in the warp and fil directions being looped around each other to maintain th integrity of the article. In addition, cut ends of th article can be fused together by heat and/or sealed off wit epoxies or rubber cement to prevent fraying of the yarns Such techniques are well known in the art and need not b described herein in any great detail. Of course, at the end of the article, as would be apparent to those skilled in th art, the configuration would typically deviate somewhat in th number of warp yarns per bundle from that shown for the remainder of the article, due to the needed ending techniqu employed. The articles of the present invention can be constructe of two or more planes of warp yarns depending upon the desir ballistic resistance to be achieved by the particular article For instance, the present invention employing a singl thickness of the article can be used to replace a typical bo armor employing about 25 layers of a 2-dimensional woven hi modulus yarn, such as aramid (e.g. kevlar) , to achieve t same or greater resistance and being significantly thinn than the combined 25 layers that would be employed in t prior art. In fact, a single thickness of the high modul yarns, woven pursuant to the present invention, may provi class 3 protection (high powered rifles) .

An important advantage of the present invention is th the particular weave exemplifies a weave configuration th precludes the yarns from being pushed apart by an impingi projectile and therefore, such is effectively stopped by t article. Along these lines, see Figures 8 and 9 th illustrate the effectiveness of the present invention. Th type of weave is more effective in stopping polymer coat projectiles than prior art 2-dimensional weaves.

In particular. Figures 8 and 9 show the results of a te performed on a article made of aramide (kevlar 29 having modulus of at least about 1.5 x 10⁵ MPa) yarn about 0.2 inches thick, having the interlock configuration pursuant the present invention, wherein the thickness is 8 planes warp yarns. The denier of the Kevlar 29 is about 300 However, the deniers can be significantly higher or lowe depending upon the yarn chosen. In the test, three samples the article were placed in cardboard boxes and backed by san The samples were shot by a 0.38 special revolver loaded wi full metal jacket, 158 grain bullets from a distance of feet. As shown in Figure 8, the bullet was effective stopped by the article. Figure 9 shows that the bullet did not separate any of the yarns, thereby illustrating t advantages achieved by the present invention. In use, the article can be employed for any lightweigh armor application. In particular, the articles can b employed in preparing personal soft body armor, as well a armor for stationery and mobile objects, such as militar vehicles, automobiles, planes, helicopters and satellites When used for more typical soft body armor, such as vests, th articles of the present invention would be placed withi particular strategic pockets in a vest or a jacket, a conventionally done with the prior art ballistic resistan woven materials. The articles of the present invention can b fabricated by standard industrial type looms.

Various configuration that can employ the articles of th present invention are illustrated in the publication "bod armor" by Safariland, May 1992, disclosure of which i incorporated herein by reference.

Claims

What is Claimed is;

1. An article of manufacture comprising at least t planes containing a plurality of yarns in the warp directio and located in the fill direction in the first plane is first fill yarn that is woven such to bind together plurality of warp yarns; a second fill yarn is locat directly behind said first fill yarn and is shifted specified increment over in the width direction to bi together the same number of warp yarns as bonded by the fir fill yarn; a third fill yarn is located directly behind sa second fill yarn and is shifted another specified increme over in the width direction in relation to said second fi yarn to bind together the same number of warp yarns as bond by said second fill yarn and wherein this shifting arrangeme of yarns is continued throughout substantially the enti width of the warp direction; and wherein the angle created the change in direction of any individual fill yarn is abo 45 to about 75 degrees.

2. An article of manufacture comprising at least t planes containing a plurality of yarns in the warp directio wherein the yarns in one warp plane are offset from the yar in an adjacent warp plane by at least one yarn in the wid direction; and located in the fill direction in the fir plane is a first fill yarn that is woven such to bind togeth a plurality of warp yarns; a second fill yarn is locat directly behind said first fill yarn and is shifted specified increment over in the width direction to bi together the same number of warp yarns as bonded by the fir fill yarn; a third fill yarn is located directly behind sa second fill yarn and is shifted another specified increme over in the width direction in relation to said second fi yarn to bind together the same number of warp yarns as bond by said second fill yarn and wherein this shifting arrangeme of yarns is continued throughout substantially the enti width of the warp direction, thereby providing an interlocke three dimensional article.

3. The article of manufacture of claim 2 wherein th article contains as many planes of warp yarns as required fo a desired thickness.

4. The article of manufacture of claim 2 wherein th article contains four to eight planes of warp yarns.

5. The article of manufacture of claim 4 wherein th warp yarns in one warp plane are offset from the warp yarns i the planes adjacent thereto by one yarn in the widt direction, and wherein the planes adjacent to said one war plane are aligned with each other.

6. The article of manufacture of claim 1 wherein sai angle is about 60 degrees.

7. The article of manufacture of claim 1 where th yarns in all directions are of the same material.

8. The article of manufacture of claim 1 wherein th yarns in the warp direction is of a different material tha the yarn in the fill direction.

9. The article of manufacture of claim 2 wherein th yarns in all directions are of the same material.

10. The article of manufacture of claim 2 wherein th yarn in the warp direction is of a different material than th yarn in the fill direction.

11. The article of manufacture of claim 2 wherein th angle created by the change in direction of any individua fill yarn is about 30 to about 120 degrees.

12. The article of manufacture of claim 11 wherein sai angle is about 45 to about 75 degrees.

13. The article of manufacture of claim 11 wherein sai angle is about 60 degrees.

14. The article of manufacture of claim 1 wherein sai yarns are selected from the group consisting of aramid, glass quartz, polyolefins, polyesters, nylon, polybenzothiozole polybenzoxizole, silk and mixtures thereof.

15. The article of manufacture of claim 2 wherein sai yarns are selected from the group consisting of aramid, glass, quartz, polyolefins, polyesters, nylon, polybenzothiozole polybenzoxizole, silk and mixtures thereof.

16. The article of manufacture of claim 1 wherein sai yarns are of aramid.

17. The article of manufacture of claim 2 wherein sai yarns are of aramid.

18. The article of manufacture of claim 1 being in th form of armor.

19. The article of manufacture of claim 17 being in th form of personal body armor.

20. The article of manufacture of claim 17 being in th form of armor for vehicles, planes and satellites.

21. The article of manufacture of claim 2 being in th form of armor.

22. The article of manufacture of claim 20 being in th form of personal body armor.

23. The article of manufacture of claim 20 being in th form of armor for vehicles, planes and satellites.

24. The article of manufacture of claim 1 wherein yarn in the warp direction or the fill direction or both are o different material.

25. The article of manufacture of claim 2 wherein yarn in the warp direction or the fill direction or both are o different material.